Introduction:  Severity of bronchiectasis is often described in terms of radiological features. However few studies have demonstrated how these radiological features reflect disease severity and clinically meaningful outcomes. We aim to assess to what extent does bronchial dilatation in cylindrical Bronchiectasis influence severity and clinical outcomes.


Methods: CT scans from patients with Bronchiectasis attending a specialist clinic were analysed by 2 blinded researchers. Cases of Varicose or Cystic bronchiectasis were excluded. Bronchial-arterial ratio (BAR) was calculated in the 3 most affected segments and the maximal ratio recorded. Presence of mucous plugging and emphysema were also recorded.  Clinical characteristics including Bronchiectasis Severity Index (BSI) score were recorded.

Results:  142 CT scans were reviewed. The Mean age was 68.8, 56% of patients were female. Mean exacerbation frequency was 2.5/year. Mean BAR was 1.33, 41 scans (28.9%) had mucous plugging, 57 (10.1%) had significant emphysema. Mean BSI was 6.6. There was no correlation between BAR and BSI (r=0.1159, p=0.23) or BAR and FEV1 (r=0.065, p=0.6), or BAR and Exacerbation frequency (r=-0.005, p=0.96). There was weak correlation between presence of Emphysema and BSI (p=0.035). There was no strong correlation between frequent exacerbator status and radiological parameters.


Conclusion:  In Cylindrical Bronchiectasis CT features have little relationship with clinically meaningful endpoints such as exacerbation frequency or established severity assessments. Bronchiectasis severity should be assessed in a multidimensional manner rather than relying on radiology.